1. Field of the Invention
The present invention generally relates to techniques for scanning through a display screen, where such a display screen has a see-through feature and may include but not be limited to, a liquid crystal display (LCD). The scanning is achieved by a sensing mechanism disposed behind a display screen when the display screen is set for a moment of see-through so that scanning through the display screen is achieved.
2. Description of the Related Art
There are many applications that need optical scanners to convert paper-based objects, such as texts and graphics, to an electronic format that can be subsequently analyzed, distributed and archived. One of the most popular optical scanners is a flatbed scanner that converts scanning objects, including pictures and papers, to images that can be used, for example, for designing World Wide Web pages and optical character recognition. Another popular optical scanner is what is called sheet-fed scanners that are small and unobtrusive enough to be carried around, hence referred to as mobile scanners, to provide a handy scanning means.
A mobile scanner comes handy and is often used to convert actual printed or written materials into electronic format. For example, a journalist goes far away from a news bureau to collect information about an important event there. It is considerably useful that such a portable or mobile scanner can be used to scan documents on site into a computer that then forwards the electronic versions to the news bureau for immediate news reporting or archival.
Many latest mobile devices are equipped with one or more cameras. For example, iPhones from Apple Inc. are equipped with two cameras, one on the front and the other on the back to allow a user to capture video or images for various purposes. Although the image quality of such cameras is improving over the time, it is difficult to use such cameras to capture documents in good quality. Thus, various scanners are still holding their market shares and being used in applications they have been designed for.
Biometrics recognition is getting popular lately. It refers to metrics related to human characteristics (e.g., fingerprints). Biometrics authentication is used in computer science as a form of identification and access control. iPhone 5 may be the first smartphone equipped with the capability to capture a fingerprint of a user for authentication. Specifically, a touch ID (being Apple's name for the new biometric fingerprint authentication technology) is built into the home button of an iPhone. The touch ID features a stainless steel detection ring to detect the fingerprint without the user having to pressing it. There is no shape drawing in the home button. The sensor behind uses capacitive touch to detect the fingerprint of the user. The sensor used in iPhone 5S has a thickness of 170 μm with 500 pixels per inch resolution and can capture the fingerprint of a finger oriented in any direction.
As the name suggested, the touch ID on iPhone is for capturing a fingerprint and of almost no use to capture anything else. With the popularity of smartphones, a user would like to use his smartphone to do more than identification and access control. In the case of currency bill verification, neither the touch ID nor the camera could be used to verify whether a received currency bill (e.g., a $100 bill) is genuine or counterfeited.
Thus there is a need for technology that can be used to read or scan a large object on a computing device, especially those portable ones, where such technology shall not increase the size of the device when used. With the popularity of the smartphones, there is a demand that a smartphone can be used for authentication and access control. However, just relying on a single fingerprint is weak. It is believed that techniques for scanning more than one fingerprints at the same time shall be welcome and useful in the market.
There is also a need for technology that can be used to read or scan certain marks on an object that are not visible under normal lighting. It is believed that techniques for scanning such marks with a portable device shall be welcome and useful in the market.